Cardiovascular and neuropsychiatric safety of smoking cessation pharmacotherapies in non-depressed adults: a retrospective cohort study

First Episode of Psychosis in the Context of Varenicline Treatment for Smoking Cessation

Smoking is one of the leading causes of preventable death worldwide. Several pharmacological therapies have been established over the years to aid in smoking cessation, including Varenicline, a partial nicotine agonist. Neuropsychiatric adverse events have been reported in patients treated with Varenicline. Here, we present a case of first-episode psychosis in the context of Varenicline therapy. The patient's chart was retrospectively reviewed for relevant medical and psychiatric history, in addition to the use of current or past medications. Routine laboratory investigations and brain imaging were performed. The Naranjo Adverse Drug Reaction Probability Scale was also done independently by two physicians involved in the patient's treatment. He was admitted for psychotic symptoms elicited in the context of a probable adverse reaction to Varenicline. The current evidence linking Varenicline to psychosis remains controversial. Speculatively, there could be a link between Varenicline, which supposedly increases dopamine levels in the prefrontal cortex through the mesolimbic pathways, and psychotic symptoms. It is therefore beneficial to be cognizant, in a clinical setting, of the possibility of the emergence of these symptoms with Varenicline therapy.

Study title: A systematic review of RCTs to examine the risk of adverse cardiovascular events with nicotine use

Associations between cigarette smoking and increased risk of cardiovascular disease are well established. However, it is unclear whether the association is mediated by exposure to nicotine and/or to other constituents in cigarette smoke. The objective of this systematic review and meta-analysis of randomized control trials (RCTs) was to identify any potential associations between exposure to nicotine and the risk of clinically diagnosed adverse cardiovascular events in adult current users and nonusers of tobacco products. Among 1,996 results, 42 studies, comparing nicotine and non-nicotine groups, were included and were both qualitatively and quantitatively synthesized across the outcomes of arrhythmia, nonfatal myocardial infarction, nonfatal stroke, and cardiovascular death. The majority of studies evaluating nonfatal myocardial infarction, nonfatal stroke, and cardiovascular death reported no events that occurred in either the nicotine or non-nicotine control groups. Among the studies that reported events, rates of adverse events were similarly low between both groups. Consistent with findings from previous systematic reviews and meta-analyses, pooled data showed that rates for arrhythmia, nonfatal myocardial infarction, nonfatal stroke, and cardiovascular death were not significantly different between nicotine and non-nicotine groups. The overall quality of the body of evidence for each of the four outcomes of interest was graded as "moderate," limited only by the imprecision of results. The findings of this systematic review and meta-analysis indicate that, with moderate certainty, there are no significant associations between the use of nicotine and the risk of clinically diagnosed adverse cardiovascular events-specifically, arrhythmia, nonfatal myocardial infarction, nonfatal stroke, and cardiovascular death.

Use of Contrave, Naltrexone with Bupropion, Bupropion, or Naltrexone and Major Adverse Cardiovascular Events: A Systematic Literature Review

Naltrexone/Bupropion extended release (ER; Contrave) is an extended-release, fixed-dose combination medication of naltrexone (8 mg) and bupropion (90 mg) for patients with obesity or overweight with at least one weight-related comorbidity. Obese and overweight patients with or without comorbidities are at increased cardiovascular (CV) risk. Due to the increased CV risk profile in this patient population, this systematic literature review was conducted to assess human studies reporting major adverse CV events (MACE) and other CV events. A priori eligibility criteria included clinical studies (randomized and observational) published from January 1, 2012, to September 30, 2021, with data comparing users of naltrexone/bupropion ER, naltrexone with bupropion, bupropion without naltrexone, or naltrexone without bupropion versus comparator groups (placebo or other treatments), and with sufficient information to determine the frequency of MACE or other CV adverse events by treatment group. Among 2539 English-language articles identified, 70 articles met the eligibility criteria: seven studies of naltrexone/bupropion ER or naltrexone with bupropion, 32 studies of bupropion, and 31 studies of naltrexone. No studies reported an increased risk of MACE among users of naltrexone/bupropion ER, naltrexone with bupropion, or bupropion or naltrexone individually compared with nonusers. One-half of the available studies (n = 35) reported no (zero) CV events and the other half (n = 35) reported that a non-zero frequency of CV events occurred. Four studies reported data on MACE, including three studies of bupropion and one study of naltrexone/bupropion ER. For composite MACE and its components, the difference in proportions between naltrexone/bupropion ER-, bupropion-, or naltrexone-treated patients compared with active comparators or placebo-treated patients did not exceed 2.5%. In conclusion, the available human evidence does not indicate an increased risk of CV events or MACE following use of naltrexone/bupropion ER, naltrexone with bupropion, or the individual components.

Comparison of Cardiovascular Safety for Smoking Cessation Pharmacotherapies in a Population-Based Cohort in Australia

IMPORTANCE

Although concerns exist regarding a potential increased risk of cardiovascular events for smoking cessation pharmacotherapies, there is general consensus that any increased risk associated with their use would be outweighed by the benefits of smoking cessation; thus, clinical guidelines recommend that such pharmacotherapies be offered to everyone who wants to quit smoking. In the interest of minimizing risk to patients, prescribers need evidence indicating how these pharmacotherapies compare with one another in terms of cardiovascular safety.

OBJECTIVE

To compare the risk of major adverse cardiovascular events (MACE) among individuals initiating varenicline, nicotine replacement therapy (NRT) patches, or bupropion.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, population-based cohort study using linked pharmaceutical dispensing, hospital admissions, and death data was conducted in New South Wales, Australia. Participants included adults who were dispensed a prescription smoking cessation pharmacotherapy between 2008 and 2015 or between 2011 and 2015, depending on the availability of the pharmacotherapies being compared. Pairwise comparisons were conducted for risk of MACE among 122 932 varenicline vs 92 148 NRT initiators; 342 064 varenicline vs 10 457 bupropion initiators; and 102 817 NRT vs 6056 bupropion initiators.

EXPOSURE

First course of the smoking cessation pharmacotherapy of interest.

MAIN OUTCOMES AND MEASURES

The primary outcome was MACE, defined as a composite of acute coronary syndrome, stroke, and cardiovascular death. Secondary outcomes were the individual components of MACE. Inverse probability of treatment weighting with high-dimensional propensity scores was used to account for potential confounding. Cox proportional hazards regression models with robust variance were used to estimate hazard ratios (HRs) and 95% CIs. Data were analyzed January 24, 2019, to September 1, 2021.

RESULTS

The mean (SD) age of included individuals ranged from 41.9 (14.2) to 49.8 (14.9) years, and the proportion of women ranged from 42.8% (52 702 of 123 128) to 52.2% (53 693 of 102 913). The comparison of 122 932 varenicline initiators and 92 148 NRT patch initiators showed no difference in the risk of MACE (HR, 0.87; 95% CI, 0.72-1.07) nor in the risk of the secondary outcomes of acute coronary syndrome (HR, 0.96; 95% CI, 0.76-1.21) and stroke (HR, 0.72; 95% CI, 0.45-1.14). However, decreased risk of cardiovascular death was found among varenicline initiators (HR, 0.49; 95% CI, 0.30-0.79). The results of comparisons involving bupropion were inconclusive owing to wide confidence intervals (eg, risk of MACE: 342 064 varenicline vs 10 457 bupropion initiators, HR, 0.87 [95% CI, 0.53-1.41]; 102 817 NRT patch vs 6056 bupropion initiators, HR, 0.79 [95% CI, 0.39-1.62]).

CONCLUSIONS AND RELEVANCE

The finding of this cohort study that varenicline and NRT patch use have similar risk of MACE suggests that varenicline, the most efficacious smoking cessation pharmacotherapy, may be prescribed instead of NRT patches without increasing risk of major cardiovascular events. Further large-scale studies of the cardiovascular safety of varenicline and NRT relative to bupropion are needed.

Risk of neuropsychiatric and cardiovascular adverse events following treatment with varenicline and nicotine replacement therapy in the UK Clinical Practice Research Datalink: a case-cross-over study

BACKGROUND AND AIMS

Varenicline and nicotine replacement therapy (NRT) are the most commonly used medications to quit smoking. Given their widespread use, monitoring adverse risks remains important. This study aimed to estimate the neuropsychiatric and cardiovascular risks associated with varenicline and NRT as used in routine UK care.

DESIGN

Case-cross-over study.

SETTING

UK-based electronic primary care records in the Clinical Practice Research Datalink from 2006 to 2015 linked to hospital and mortality data sets.

PARTICIPANTS

Adult smokers (n =282,429) observed during periods when exposed and not exposed to either varenicline or NRT.

MEASUREMENTS

Main outcomes included suicide, self-harm, myocardial infarction (MI), all-cause death and cause-specific death [MI, chronic obstructive pulmonary disease (COPD)]. In primary analyses, conditional logistic regression was used to compare the chance of varenicline or NRT exposure during the risk period (90 days prior to the event) with the chance of exposure during an earlier single reference period (91-180 days prior to the event) or multiple 90-day reference periods to increase statistical power.

FINDINGS

In the primary analyses, findings were inconclusive for the associations between varenicline and the main outcomes using a single reference period, while NRT was associated with MI [odds ratio (OR) = 1.40, 95% confidence interval (CI) = 1.18-1.67]. Using multiple reference periods, varenicline was associated with an increased risk of self-harm (OR = 1.32, 95% CI = 1.12-1.56) and suicide (OR = 3.56, 95% CI = 1.32-9.60) but a reduction in all-cause death (OR = 0.75, 95% CI = 0.61-0.93). NRT was associated with MI (OR = 1.54, 95% CI = 1.36-1.74), self-harm (OR = 1.30, 95% CI = 1.18-1.44) and deaths from MI (OR = 1.53, 95% CI = 1.11-2.10), COPD (OR = 1.33, 95% CI = 1.14-1.56) and all causes (OR = 1.28, 95% CI = 1.18-1.40) when using multiple reference periods.

CONCLUSIONS

There appear to be positive associations between (1) nicotine replacement therapy (NRT) and myocardial infarction, death and risk of self-harm and (2) varenicline and increased risk of self-harm and suicide, as well as a negative association between varenicline and all-cause death. The associations may not be causal. They may reflect health changes at the time of smoking cessation (nicotine replacement therapy is prescribed for people with cardiac problems) or be associated with quit attempts (exposure to both medicines was associated with self-harm).

Comparative Safety of Smoking Cessation Pharmacotherapies During a Government-Sponsored Reimbursement Program

INTRODUCTION

The British Columbia Ministry of Health launched a Smoking Cessation Program on September 30, 2011, providing financial coverage for smoking cessation pharmacotherapies. Although pharmacotherapies have been shown to have a moderate short-term benefit as a quitting aid, substantial cardiovascular and neuropsychiatric safety concerns have been identified in adverse-reporting databases, leading to prescription label warnings by Health Canada and the U.S. Food and Drug Administration. However, recent studies indicate these warnings may be without merit. This study examined the comparative safety of medications commonly used to aid smoking cessation.

AIMS AND METHODS

Population-based retrospective cohort study using B.C. administrative data to assess the relative safety between varenicline, bupropion, and nicotine replacement therapies (NRTs). The primary outcome was a composite of cardiovascular hospitalizations. Secondary outcomes included mortality, a composite of neuropsychiatric hospitalizations, and individual components of the primary outcome. Statistical analysis used propensity score-adjusted log-binomial regression models. A sensitivity analysis excluded patients with a history of cardiovascular disease.

RESULTS

The study included 116 442 participants. Compared with NRT, varenicline was associated with a 10% 1-year relative risk decrease of cardiovascular hospitalization (adjusted risk ratio [RR] = 0.90, 95% confidence interval (CI): 0.82 to 1.00), a 20% 1-year relative risk decrease of neuropsychiatric hospitalization (RR: 0.80, CI: 0.7 to 0.89), and a 19% 1-year relative risk decrease of mortality (RR: 0.81, CI: 0.71 to 0.93). We found no significant association between NRT and bupropion for cardiovascular hospitalizations, neuropsychiatric hospitalizations, or mortality.

CONCLUSIONS

Compared with NRT, varenicline is associated with fewer serious adverse events and bupropion the same number of serious adverse events.

IMPLICATIONS

This study addresses the need for comparative safety evidence in a real-world setting of varenicline and bupropion against an active comparator. Compared with NRT, varenicline was associated with a decreased risk of mortality, serious cardiovascular events, and neuropsychiatric events during the treatment, or shortly after the treatment, in the general population of adults seeking pharmacotherapy to aid smoking cessation. These results provide support for the removal of the varenicline boxed warning for neuropsychiatric events and add substantively to the cardiovascular safety findings of previous observational studies and randomized clinical trials.